This proposal is for the New England College of Optometry (NEWENCO) to serve as one of five clinical centers in the Vision In Preschoolers (VIP) Study. The VIP Study is a prospective, clinical trial designed to develop an effective and efficient battery of screening tests to identify those 3-and 4-year-old Head Start children in need of further vision care for amblyopia, strabismus, and/or significant refractive error, that are the prevalent significant vision disorders of early childhood. To accomplish these goals, a battery of screening tests will be administered to at least 1278 3- and 4 year-old children enrolled in Head Start centers in Boston. The battery consists of tests chosen for their design characteristics, validity, and applicability to the preschool population, and includes the Massachusetts Visual Acuity Test modification of the Lea Symbols test at distance, Random Dot E stereotest, and refraction via the Retinomax monocular autorefractor. The battery of tests will be administered at Head Start sites by lay people (Head Start parents) which ensures availability of screeners, utilizes persons with a vested interest in benefiting children, and maximizes the applicability of this model to other communities. Each child who fails the screening or is untestable, and a randomly selected subset of children who pass the screening, will undergo a comprehensive eye examination at the NEWENCO Clinical Center. The examination will serve as the definitive method, or gold standard, for detection of the target disorders. The sensitivity and specificity for detection of the target disorders will be determined for each of the screening battery tests alone, and in combination. This application documents: a) access of the NEWENCO Clinical Center to 1750 children enrolled in Head Start and b) that facilities and personnel are available for conducting vision screenings at the Head Start sites and for conducting gold standard eye examinations. Complete details of the VIP Study rationale, design, and methods are contained in the MOP, which is submitted with the Study Chair application.